Water-back for furnaces



S. E. DIESCHER.

WATER BACK FOR FURNACES. APPLICATION FILED) AUG. 13, 1918- RENEWED JUNE 9. 1920.

Patented Dec. 28, 1920.

INVENTOR o a M b. RM $103M am I WITNESSES UNITED S'TA'ILES PATENT OFFICE.

SAMUEL E. DIESCHER, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO DARWIN S.

WOLCOT 'I, TRUSTEE, OF SEWICKLEY, PENNSYLVANIA.

Specification of Letters Patent.

Patented Dec. 28, 1920.

Application filed August 13, 1918, Serial No. 249,648. Renewed June 9, 1920. Serial No. 387,781.

To all whom it may concern Be it known that I, SAMUEL E. Drnsonnn, residing at \Vilkinsburg, in the county of Allegheny and State of Pennsylvania, a citizen of the United States, have invented or discovered certain new and useful Improvements in ater-Backs for Furnaces, of which improvements the following is a specification.

In operating furnaces embodying mechanism whereby there is a continuous movement along the fuel supports to the ash grate, plate or dump, it is usual to employ a forced'draft and the temperature within the furnace is raised to a point at which the non-combustible material in the fuel will be fused and form in masses of greater or less size. As in the operation of the stoking mechanism the bed of fuel is not broken up, the agglomeration of the softened or fused material is facilitated, and as the material including ashes and softened clinkers move through the furnace and across the dumpplate such clinker as will come in contact with the highly heated walls of the furnace while in a softened condition will adhere thereto. In a comparatively short time, especially if the fuel is of a low grade, 2'. 6., contains a large percentage of foreign material, the clinkers will accumulate to such an extent as to retard the movement of the material adjacent to the side walls and to clog the ash discharge, and the clinkers, must be broken up and dislodged from the wall of the furnace by hand-operated means during which time furnace conditions cannot be maintained normal due to shutting off of the draft, opening of doors, etc., all resulting in a temporary loss of efliciency.

The invention described herein has for its object the provision of means for so chilling the clinkers formed during the combustion of the fuel that they will not adhere to the wall of the furnace and also to effect such a disintegration of the masses of clinker that they will be capable of passing through the normal opening provided for the discharge of ashes. The invention is hereinafter more fully described and claimed.

In the accompanying drawings forming a part of this specification, Figure l is a sectional elevation of'a furnace having my improvement combined therewith; Fig. 2 is a similar View showing a modification of the improvement and Fig. 3 is a sectional detail showing a further modification of the water back.

I 01- purposes of illustration and description, the lmprovement clalmed herein is shown in connection with a stoking mecha-v -materials in the fuel from the furnace or onto the ash supporting plate or grate 7 and thence to the ash pit. In the construction shown provision is made for shifting the movable members of the fuel supporting surface longitudinally to advance the fuel, but any suitable means known in the art may be employed for moving the fuel through the furnace. The bars are provided with notches 8 for the reception of the ends of arms 9 on a shaft 10, which is also provided with an arm 11 having its outer end connected by a rod 12 to one end of a lever 13 having its opposite end connected to the fuel feeding plunger 4;. While the,

fected in any suitable manner known in the art, as for example, by a movement of the plate relative to the ends of the grate bars or a movement of the latter relative to the plate, or the simultaneous relative movements of the bars and plate. It is preferred that the ash plate should be so supported that its inclination from a horizontal plane whi le its operativeposition is determined by an arm 15 on the shaft 16. The lever 14 is connected by a rod 17 to a second lever 18 operated to reciprocate the plate by the plunger 4. The shaft 16 is rotatable to suitable means.

As a consequence of this maintenance of the substantial integrity and continuity of the bed of fuel the foreign material therein is carried along and given an opportunity.

of agglomeratingand adhering to such walls of the furnace with which such softened and agglommerated masses may be brought into contact. As all the ashes and clinker will pass over the ash plate or dump and nearly all come into'contact with the rear wall of the furnace, the clinker will agglomcrate such large masses and adhere in such quantities as to preclude the discharge of ashes and clinker from the dump plate, and the lumps have to be broken up and detached from the furnace or the ash plate so shifted as to permit the (lischarge of the clinker and ashes. This operation is not only difiicult but the shifting of the ash plate to discharge the large lumps will permit of the discharge of all the ashes thereon, thus leaving the portion of the grate bars adjacent to the dump plate uncovered.

In addition to this formation of large lumps of clinkers, the soft viscous clinker is brought into contact With the walls forming the rear of thefurnace and portions of the discharge opening for the ashes and as these Walls are generally formed of brick and are highly heated, the clinkers will adhere thereto in such quantities as to prevent the discharge of ashes from the furnace.

In order to overcome these objections, provision is made to prevent the adherence of the clinker to walls of the furnace'and to effect such a disintegration of the lumps of clinkers while supported in the furnace as will permit the discharge of all the material through the normal opening provided for the discharge of the ashes.

The first of these objects is attained by providing means on the level of the movement of the fuel through the furnace and of the ashes just prior to their discharge into the pit as for example above but adjacent to the ash plate for chilling the surfaces of the masses of clinkers to such a degree as to destroy" their adhesivene'ss. To this end a portion-of the wall of the furnace and especially adjacent to the ash plate where clinker is liable to adhere is formed by a a low temperature by the circulation of a cooling medium along the side opposite that subjected to the heat of'the furnace. This metal surface may be formed by a portion of the wall of a pipe 20 so embedded in'the wall of the furnace that material, 2'; 'e., clinkers, etc., moving through the furnace to the opening to the ash pit will come into contact witha portion of the surface of the 'pipe. Water, air or other cooling medium change the 1ncl1nat1on of the plate by any is caused to flow through the pipe so as to maintain the surface with which the clinkers will contact, sufficiently cool so that the surfaces of the masses of clinkers will be chilled to such an extent as to prevent their adherence to the wall of the furnace.

As is well known, the projection of jets of steam against highly heated clinker will cause a disentegration of the lumps into comparatively small particles, and in order.

toreduce the large lumps or masses of clinkers before reaching the opening into the pit to such small dimensions that the clinkers will pass freely through the opening normally provided, a pipe 21 connected to'a steam supply is so arranged that jets of steam escaping through perforations in the pipe 21 will impinge on the lumps of clinker at points or along lines intermediate the normal'level of material in the furnarie and the members supporting such materia I It is characteristic of the invention described herein that the clinker will not 001- lect onthe wall of the furnace and willbe brought in the normal operation of the furnace to position where the lumps will be disintegrated'by the action of thesteam and will thereafter pass easily into the pit.

When employing a section of plpe as a water Wall it is preferred that one side should be flattened as shown in Fig. 2 and if desired a longitudinal recess 22 may be formed for the reception of the steam pipe, as shown in Fig. 3.

The feed of water to the water wall 23 is so controlled by suitable means-as to maintain an approximately constant level of water within the shell, and passages are provided connecting the space above the normal water level to constantly open outlets below the level. In the' construction shown herein, these passages are formed of a plurality of pipes 24 arranged diagonally across the shell and connecting with .the outlets 25. The regulation of the feed water through the pipe 11 into the shell 5. As the level of the water in the Water wall lowers through the'escape of steam through the outlets, the float will move down opening the valve 31 to admit the inflow of water to the water wall to restore the water to the desired level.

It is characteristic of the invention described and claimed herein that a metal wall cooled to a temperature below that at which clinker is adherent is provided at points or along lines in the furnace where hot clinker moving through the furnace to the ash discharge openings will contact therewith. By reason of the low temperature of the metal wall, the clinker will be prevented from adhering to the latter. The clinker cooling wall should extend from points below the normal surface of the fuel and ashes in the furnace to points or planes at least approximately coincident with and preferably somewhat above' the normal level of material in the furnace. It is also characteristic of the invention that by the movement of the fuel and the ashes the furnace clinkers which are formed during such movement will be finally brought into the sphere of action of the jets of steam and be thereby so disintegrated as to ,pass around the discharge edge of the ash plate in the position to which it is adjusted in the normal operation of the furnace.

I claim herein-as my invention:

1. In a furnace thecombination of means for causing a progressive movement of fuel through the furnace, a metal wall adjacent to the region of clinker adherence, means for applying a cooling medium to such wall and means for directing jets of steam into the highly heated material passing through the furnace from points below the portion of the metal wall in contact with the fuel or ashes and at points or along lines intermediate the normal level of material in the furnace and the. means for supporting and causing the movement of the material through the furnace.

2. In a furnace the combination of means for causing a progressive movement of material through the furnace, a closed shell sup ported in the region of clinker adhesion, means for supplylng water to said shell and means for directing steam generated in the shell into the material at points below the nlprlmal levelof material in contact with the s e l.

3. A water wall for combustion chambers having in combination a closed shell adapted to be supported in the chamber in the region of clinker adhesion and provided with a normally open outlet arranged below the normal level of water in the shell and discharging into the region of clinker adhesion in the combustion chamber and means for so regulating the flow of water to the shell as to maintain a steam collecting space in the shell and a connection from such steam collectin space to the outlet from the shell.

.4. A combustion chamber having in combination fuel supporting members, ash supporting members, a closed shell provided with a normally open outlet arranged below the normal level of water in the shell and so supported in the chamber that the outlet will be in such position relative to the ash supporting member as to discharge steam into the ashes supported by said members, means for supplying water to said shell, means for segregating the steam generated in the shell and connecting it to said outlet.

5. A water wall for-combustion chambers having in combination a closed shell provided with an outlet below the normal level of water in the shell and adapted to be so supported in the chamber as to discharge the steam generated in such shell into the region of clinker formation, means for. supplying,

water to the shell, and a passage extending from a point within the shell above the normal water level to the outlet.

6. A combustion chamber having in combination a closed. shell supported in the chamber in the region of clinker adhesion means for so supplying water to the shell as to maintain a steam collecting space in the shell, normally open'steam discharge nozzles connected to the steam space in the shell and arranged to discharge steam into the region of clinker adhesion.

In testimony whereof, I have hereunto set my hand.

SAMUEL E. DIESCHER. 

